Obama campaigns in Florida with former GOP Gov. Charlie Crist

ST. PETERSBURG, Fla. -- President Obama appeared in Florida with former Republican Gov. Charlie Crist, whose presence he cited as evidence that his plans aren’t partisan but just plain sensible.

Crist shows that his values “are not Democratic values or Republican values,” Obama said. “They are American values.”

Introducing the president to the crowd in his state, Crist said he is no longer in the GOP because “they left me.”

The break-up occurred in 2010 after Crist left the Republican party and ran for U.S. Senate unsuccessfully as an independent. Many people expect that he’ll run for governor as a Democrat.

But the endorsement still gave Obama an opportunity to resurrect the memory of his popular line from the 2004 Democratic National Convention, when he told Democrats that the country is not made up of red states nor the blue states “but the United States.”

In the three-day campaign tour coming out of the convention, Obama is hitting the same themes and repeating specific goals for a second term that he laid out the night he accepted the party's nomination.

"I am here to tell you our problems can be solved, and our challenges can be met," Obama said here. "The path we offer may be harder, but it leads to a better place. And I’m asking you to choose that future."

While Romney is focusing efforts on the advantages their fundraising provides, the Obama operation is attempting to crank up the ground game operation they think will keep them competitive.

In addition to trying to persuade undecided voters, Obama is also trying to fire up his base supporters and motivate them to vote and to volunteer.

Field organizers are present at every event working the crowd with their clipboards to get contact information for Obama supporters and register new voters. Anyone not registered to vote in Florida by Oct. 9 will not be able to cast a ballot.

Obama advisors believe the past two weeks of political conventions didn’t change the race much, but they contend Obama positioned his campaign to activate grassroots networks.

“We are not expecting huge movement in this race all the way out to the next 60 days,” said David Plouffe, a top political advisor to the president. “But there is a chance we might have increased our turnout dynamics.”

Obama campaign officials are looking ahead to polling data of the coming days for signs of movement in the race. They don’t expect to see it, they say – or perhaps that is just their hope.

“We think we have enough support to win every battleground state,” one senior official said. “The question is, ‘Can we translate that into the kind of turnout we need to win an election?’”

Priorities USA, an outside organization supporting Obama’s candidacy, released a new 30-second ad on Saturday that accuses Romney of trying to tear down the middle class.

The spot will run on television and online in the battleground states of Colorado, Florida, Iowa, Ohio, Virginia and Wisconsin.

While the group didn't say exactly how much they are spending to air it, it's clear they don't have nearly the money at their disposal as do their rival organizations on the Republican side.